To simplify the update, you can use the plugins:
Easy Theme and Plugin Upgrades or Update Theme and Plugins from Zip File

Note please: You can download the update from the page of your account.

Step-By-Step:

Step 1: Delete the Old Version
1.1. In the admin dashboard go to Appearance > Themes.
1.2. Deactivate old version of the Theme.
1.3. Hover mouse on the target theme, click Theme Details link.
1.4. In the lower right corner of the theme window click Delete.

Step 2: Upload the New Version
2.1. After deleting the old version of the target theme, upload the newer package with latest version of the target theme.
2.2. Now you can activate the latest version of the target theme.

Note: Updating a theme maybe will reset the customize you’ve made in the previous version.

This article was last updated on February 6, 2019